1. Field of the Invention
The invention relates to sewing machine drive mechanisms, and particularly to a means for converting the rotary motion of a motor shaft into linear motion, through the use of low tolerance parts.
2. Description of the Prior Art
Rotary to linear motion converters are well known in the prior art. Needle stitch control and feed control mechanisms for sewing machine applications require precise control of the linear motion to insure stitch uniformity. Prior art used of rotary to linear motion conversion devices in sewing machines have heretofore required parts with high tolerances to insure the accuracy of the stitch and feed control. Such parts are costly to manufacture and require initial adjustments to insure their proper operation. These problems are minimized by the rotary to linear transmission device disclosed in this invention.